As risk grew, hospitals turned a blind eye

Over the course of eight years, hospitals ignored the long-term danger posed by a deceptive technician, allowing him to move from state to state endangering the lives of patients as he stole drugs. When he was finally arrested this summer, prosecutors say, David M. Kwiatkowski had committed one of the most egregious medical crimes in US history, infecting at least 39 patients throughout the country, with a life-threatening virus often spread by tainted needles. He maneuvered through 19 hospitals in eight states, despite leaving graphic evidence that he was descending into addiction. He took advantage of the plethora of short-term assignments available to him nationwide through temporary staffing agencies.